


In the Family Way

by zeryxis



Category: Underfell - Fandom, Undertale (Video Game), underswap
Genre: Multi, edgeberry
Language: English
Status: In-Progress
Published: 2016-08-03
Updated: 2017-09-22
Packaged: 2018-07-29 03:20:06
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 11
Words: 18,498
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7668175
Author URL: https://archiveofourown.org/users/zeryxis/pseuds/zeryxis
Summary: <blockquote class="userstuff">
              <p>Swapverse<br/>Alphys and Undyne have a request of Sans, and its not easy on anyone.</p><p>Comments/criticism/thoughts appreciated!</p><p>5 is an intermission addition, 6 is ch.5</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Leaving it as "Fell" when talking about FellPap, to make it a little clearer. Though SwapSans still calls him Papy(rus) to his face since the nickname is just for everyone to tell the difference if he's talking about his brother or mate.
> 
> Nothing porny here... YET =w= edgeberry in the next chapter for those who wanna know.  
> If you aren't into the M/M smut, go ahead to chapter 3 for plot continuation.

Sans sighed with a nearly-visible puff as he plopped down onto the log bench, finally done with the day's training with Alphys, sweat streaking his bones. The raptor-like Royal Captain chuckled as she put aside her spear to join the younger monster on the seat, though with far more ease and much less fatigue.

"You're doing much better, Sans," she said after a long pause. He bolted upright immediately, grinning at her with happily clenched fists.

"Ahah! Yes! I shall be able to do even MORE next time!" he replied eagerly, feeling internally very proud of garnering such praise. Alphys chuckled again, patting one of his gloved fists almost tenderly before she gestured to the bench again.

"Sit, I've something to discuss with you."

"Oh?" Sans replied, sliding back up to his seat curiously. Usually when she wanted to talk with him, it would be done over the course of their training, in between parries and exercises. He hoped it wasn't anything unpleasant. She sometimes had to deliver bad news, and had been getting better at picking the time and way to do so.

Alphys cleared her throat, seeming to suddenly lose some nerve, which he couldn't recall having seen before. It took her a few minutes to mentally prepare again, which he sat and waited as patiently as he could. A little fidgeting and some shifting in his seat couldn't be helped in such a long silence.

"Undyne-" she started, her voice lower than usual, "Undyne and I have decided that we wanted to have children."

"Oh!" Sans laughed out happily, grinning wider than usual, taking her clawed hand to shake it in excitement, "that's wonderful, Alphys! Congratulations!"

"However," she added, once he'd finished, making him pause curiously, soft blue eyes questioning, "we've found we may... not be able to."

"Oh."

He felt twice as worse as he would of had he not already given such an enthusiastic outburst in the middle of her explanation. His grip on her taloned hand turned soothing, looking up apologetically at his friend and mentor.

"I'm sorry," he said quietly, though it was only moments before Alphys continued.

"We have talked about surrogates," Alphys said, "for... part of it." His continued gaze was still curiously questioning, giving her time to explain rather than interrupting again. Muttering to herself, "Undyne would've explained better..." before clearing her throat again and looking at Sans.

"It's not an issue of fertility in either of us. Undyne thinks it's because we're both female, that it would take very exact, very hard to get to conditions, before it might work."

A long silence punctuated the conversation, something Alpys wouldn't do often. Her voice wavered slightly, something even more unlikely.

"So we talked about a surrogate... father."

Sans paused at that, believing he was starting to understand why Alphys was having this conversation with him. He looked down at his boots, thinking quietly about what she'd said. Another throat-clearing prompted him to turn his gaze up at the Royal Captain.

"She - I mean, um..." she groaned, rubbing her brow with a talon, "we wanted to ask... if you'd consider being the surrogate," her voice quieted with each word, a slight flush of orange coating her tanned-yellow features. Sans looked at her curiously, chewing on his glove just a bit - not having been as prepared for the request as he thought he'd been. For one, he didn't know how Fell would react, seeing as the black-and-red skeleton was fiercely possessive of him, almost to the point of controlling sometimes. For another, he wasn't entirely sure how he felt about the idea.

"Look, I know this is a lot to ask," Alphys said, breaking him out of his unusually quiet contemplations, "it was a lot to consider, for us. We've spent months going over it, and we wanted to ask you first, if you'd think about it." Turning her gaze fully to the skeleton - Alphy's predatory, full-frontal gaze could be unnerving, but right now it was almost pleading, having her look straight-on at the smaller monster. "You don't have to answer right now, Sans."

"W-well..." he started with a stammer, relieved, "I s-should talk to Fell about it..." he added, but held her claw slightly, smiling reassuringly. "I'll let you know... I'll talk to him and... well, maybe."

"Thank you, Sans," she breathed, her entire frame relaxing visibly. He smiled broader, hopping up and saluting smartly.

"Captain." 

She smiled, and returned the gesture with familiar ease.

"Dismissed."

~ ~ ~ ~

On the walk home, Sans mentally chewed over what they'd discussed. On one hand, he wanted to help, though he'd never thought of either of them like that. Alphys had always been his friend, and Undyne after the two females had met. They'd been mates practically forever. He realized he'd never asked which would be the mother, flushing slightly as he mentally weighed which he'd be more willing to... he shook his head, stopping to clear his head again. 

"Ok, so either way..." he said to himself, looking back in the direction of the training grounds, then turned back towards home, resuming his pace. He continued his mental conversation, rather than wasting breath talking to himself more.

He did know that it was something very important, monsters usually only decided to have children if they felt able to protect and teach them. Sans himself recalled that his older brother had been the one to raise him once their own parents had died, though Papyrus claimed to have been too young himself to remember things clearly anymore. He did know he wasn't entirely sure what he was going to decide, but he did want to discuss it with his own mate. They'd been together for a long time, so much so that even his brother Papyrus had eased up on his protectiveness and badgering. It still sometimes came up, mostly when Fell was being aggressive towards his doppelganger or had a burst of super-possessiveness over Sans. But it had become normal for them. 

He was closer to home than he realized, stopping within view of the sturdy house. He knew Papyrus would be either downstairs watching TV or snoozing, if he was home by now. Sometimes he'd taken to staying out a little longer at his sentry post to avoid the chance of being alone in the house with Fell. Though usually the darker skeleton wasn't visiting if Sans wasn't home yet - he had his own similar duties to attend to in his world. 

Turning the handle, he knew his brother was home due to it being unlocked, and considered if he should discuss it with Papyrus too. He gave good advice a lot of the time, even when he wasn't using it himself. Then again, Alphys might not want him talking to others about it yet, it was a very personal matter. 

"Evenin' bro," he was greeted lazily, Papyrus' head tipping back to look between the back and arm of the couch at his younger sibling, "almost went lookin' for you."

"It's not that late, is it?" he asked, then checked the small clock on the wall near the kitchen.

Almost two hours later than usual. He was surprised indeed that Papyrus hadn't come looking for him. Promptness was something Sans enjoyed.

"It is, I almost made dinner myself," Papyrus joked, and Sans winced - his brother was much worse at cooking than him. He wouldn't say it, though, but did head to the kitchen without heading upstairs to change out of his gear. He did take the heavier protective gloves and chestpiece off, but otherwise just put his favorite apron on over it and got to work with dinner. Noting the empty honey bottle in the sink, he figured that was why Papyrus hadn't come after him - he'd lost just as much time in the sweet drink as Sans had in his walk and thoughts. 

Dinner didn't take long, since some of it was saved over from the night before and mixed in. He'd found Papyrus liked it a lot when he made a spaghetti-taco mix, so often he'd do just that. No shells, instead just making the taco-mix and some veggies with the pasta. It was fun to make, though took a bit more work than either dish usually did, since he liked to put it in the oven for just a bit to make the spaghetti just the slightest bit crunchy. 

At the table, Sans picked slightly at his plate, still mulling over the conversation with Alphys. He wasn't sure if Papyrus noticed, since there was a half-empty honey bottle next to his plate, but after awhile, he put his fork down and leaned over.

"You're awful quiet today," Papyrus commented. Sans hiccuped out of his thoughts, then coughed slightly, looking down at his plate.

"Just, ah, thinking." 

"Oh?" the taller skeleton's drawling voice asked, "anythin' wrong?"

"N-no..."

"You hesitated."

"Alphys just asked me somethin' and I've been thinking about it," he replied with a soft voice, working back into his dinner with a little more energy. Papyrus took a sip of honey, hooded gaze quietly questioning, but he didn't press. If it was Alphys he figured it was something Guard-related, so probably not too interesting to him in the long run.

"Well, hope ya get an answer, bro," he said with an easy grin, patting his brother on the head.


	2. Chapter 2

**Summary for the Chapter:**

> Edgeberry trash incoming!  
> It doesn't have much to do with the plot.  
> If you're not into smut, just skip this chapter. It also pushed the rating up into Explicit because I love writing me some trash.

Having finished the dishes, Sans was upstairs cleaning up after his training, contemplating again on what Alphys had proposed. He rubbed a washcloth over his bones as he mulled over how he'd bring it up to Fell and how to best avoid making him immediately refuse in possessive defiance. Sans wanted to help his friends, and Alphys had said they'd been discussing it for months. And they'd come to him first. 

If anything, he was a little proud of that. He had been their first choice for help when they were having a near-impossible task on their own. Working a little faster, he decided he'd talk with Fell about it the next time he visited. Sans wasn't sure if he was entirely on board, but he knew he wasn't going to just say no, either. He had misgivings on the whole thing, but always wanted to help anyone he could. Once he was done cleaning, he wrapped himself in a thick fluffy towel and went to his room, dropping to the bed with a contented sigh. He'd at least sleep on it, he knew he didn't have training tomorrow, just patrol and some re-configuring of puzzles. Sitting up, the skeleton contemplated if he'd dress for bed or not.

"You needn't get up," the heavy, rough voice said from behind him, pulling the smaller skeleton from the edge of the bed and into his lap using the towel. Sans chuckled, sometimes still surprised by how deathly silently the larger monster could move. Turning in place, Sans pushed up to meet with a clack of teeth, a greeting kiss.

"Didn't think you'd be over again so soon," Sans commented. Fell chuckled darkly, pulling the towel up over San's shoulders to pull him closer for another bone-clacking kiss, already licking a little at his cheek.

"Change of plans," he replied simply, focusing his attentions to Sans' neck, nibbling at the vertebrae as Sans started to cling softly to him. Lightly scraping his jagged fangs over the smoother bone, he lapped at the spot afterwards, moving slowly down to the clavicle to bite a little harder, giving a teasing growl.

Sans whimpered, already growing flushed and hot with the tender ministrations - Fell could switch between gentle and rough without warning, something Sans found to be absolutely, heatedly maddening. Then the tongue was just tickling and lapping at his neck, making him giggle as it caressed his bones, looking up with his starry-blue eyes glimmering in joy.

"You're overdressed!" he said playfully, though his voice was breathily flustered, tugging slightly at the taller skeleton's velvety-red scarf. He laughed, a dark, rumbling sound - like thunder in the night - and smoothly began disrobing, letting the smaller male put the clothing and armor aside. Once done, Sans pulled off his towel and draped it over the neatly-bundled gear.

"Better?" Fell asked simply in a hushed voice, getting a reassuring, eager nod.

"Better! Now, there was somethin..." he tapped his chin thoughtfully, then with a burst of energy, bounded up to straddle the larger skeleton's hip, "Ah! Now I remember! You said last time I could have a turn!" 

"You remembered."

"I don't forget what you tell me, Papy," he said proudly, then prodded gently, "c'mon, you promised."

"That I did," Fell sighed, clearly feigning the tone of begrudging agreement. Sans chuckled, laying atop his mate and nudging kisses to the battle-rough bones of his ribs. Fell groaned in appreciation, shifting just enough to give the blue-eyed monster full access to his ribcage. The friction of their hips had the smaller male gasp in enjoyment, already glowing lightly blue in his hips and mouth. Running his talons lightly up the smoother, nearly pristine bones of Sans' arms, Fell laced their fingers together with a fanged smirk.

"Sure you don't want me to-"

"No! It's my turn!" he laughed happily. Loosing his fingers from Fell's grip, he ran them over the larger male's sternum, rewarded with a pleased growl. He moved to give attention to each rib, plucking very slightly before moving to the next. From the upward grind of Fell's hips against his, he could tell that he was enjoying it. Leaning down, he pressed a firm kiss to his sternum, just at the very bottom edge, only to have Fell's hands suddenly holding his head with a shuddering moan, prompting him to turn his gaze upward to the lust-addled red gaze.

"You are seriously turning me on, precious," his voice purred, sending a shiver deep down Sans' spine and straight to his hips.

"That's the idea," he answered back with a playful grin, then lowered again to wrap his tongue around the underside of Fell's sternum, a hiss of pleasure rising in his mate's clenched teeth. Pressing his teeth to the top, he suckled lightly on the curve of bone as his fingers again strummed at the broad, heavy ribs, blushing furiously as he couldn't help the slightly whining moans rising in his throat, nor the prominant, sky-blue arousal grinding down against Fell. The larger skeleton moved a hand to tease at the smaller male's shaft, only for him to lightly slap the hand away, giggling against the bone in his mouth. Fell smirked as his lover toyed with him, arching up to rub his own deep crimson arousal against one of his curved ischium; Sans gasped, lifting his head up a little as his tongue lolled out again at the pleasing touch, only to puff like an offended kitten and pull back his composure. Despite his fierce blush and slick, shivering arousal, he shifted to grip Fell's wrists, straddling his ribs, and pushed his arms back against the wall that served as the headboard to his bed.

"You're getting better at it, though," Fell admitted with a pleased grin, tipping his brow to Sans' with a clack, then tilting to get a kiss, only for Sans to deny him, pulling back enough that no further connection was made. It made the smaller of the pair ache to return the kiss, but he wanted his turn, like Fell said he could have.

"N-not done, either," he insisted, the light stammer making the fierce red eyelights flicker in enticed amusement.

"Really... what else do you have for me, precious?" 

Instead of answering, he leaned in and gave the lightest of kisses, pulling back again when Fell tried to press for more. When Sans let go of his wrists, he noticed there was a soft blue ribbon of magic tied around them. More show than substance, the ribbon would be easy to break with hardly a flick of the arm, but he noticed the stern look Sans was giving him, and smirked, putting his bound wrists up and resting them atop his head. Once he did, Sans gave him another kiss, giggling softly before leaning down to give a delicate nibble at his neck, trailing his tongue and heading for his clavicle, scraping his teeth lightly on the bone, and then biting down hard.

"SANS!" Fell exclaimed in a moan, not having expected the sudden bite, bucking his hips and having to quickly restrain himself to keep from tearing his light bondage. He felt the teeth grinding down at the bone, loosening just a bit to let the bright blue, blushing features look up at him. Once he met Sans' gaze, he felt the teeth clamp down again, harder, the smaller male rubbing his arousal against his ribs. He felt a vibration in his bones, and was superbly aroused to realize that Sans was growling. Wanting to encourage him, the larger skeleton made as soft a moan as he could manage, rewarded with a bright flash of azure and another grinding of teeth. 

For his own part, Sans was eager to do more, and eased back, rubbing his ischium against the larger cock; Fell had to grip his own forearms to keep from tearing the wisp of ribbon, a heated growl rumbling in his chest as he looked hungrily over his mate. Sans gasped and shuddered at the lusty gaze, glowing predatory with the clear sense of 'MINE'. 

"You think you deserve more, Papy?" he asked, just barely keeping his voice from shuddering in need. In response, Fell bucked his hips under him, pushing Sans up and almost off him, rubbing his arousal and bones hard up against the smaller monster. Gasping as he leaned forward, hand braced on Fell's ribs to keep from falling against his chest, Sans instead pulled his shivering hips away, leaving Fell's throbbing cock now untouched. Giving a slight tug at a rib, he leaned up mere inches from a kiss, smiling as deviously as he could manage.

"Say please."

That gave Fell a pause, and the dusting of rose across his cheeks almost broke Sans into letting the larger skeleton have his way with him. But as he lingered, feeling his lover under him, knowing just how hard a drive he had, just how dominating and vigorous... closing his eyes a moment to regain composure, knowing he was thinking himself into giving in. 

"Please."

The way he'd said it... by the stars, Sans moaned just at the way it sounded. Quiet, almost a whisper past his usually command-giving fangs. But the look in his eyes as he said it, Sans could tell he did enjoy this playful turn today. 

"Again," he whimpered, shivering needingly.

"Please." It was almost the same tone, soft and gentle, almost begging... almost feeling as if that sound alone could get him off if he heard it enough.

His hips shifted and slid the broad tip of the arousal into him, moaning thickly as Fell couldn't resist thrusting up to meet him. Luckily he'd at least planned for that, keeping him only about halfway inside before he rolled his hips, gaining a growl of pleasure from his mate. He could see how hard Fell's hands were gripping his own radii and ulnas, scratching into the bone to keep from tearing that delicate little bit of control Sans had put on his wrists. Pushing down, he hilted the throbbing red arousal inside himself and had hardly begun to lift again when the broader hips thrust up, bouncing him up and down. Sans let him do this for a bit, loving the feel of being pushed up and having to ride down the arousal before the hips raised him again, but at one high, he continued forward until only the tip remained inside him, clenching just enough to hold.

"I was wrong, precious... you're getting -much- better," Fell panted, eyes flickering heatedly. He had gotten the hint to stop when Sans had risen up, though the grip at his glans had the red skeleton aching to have his turn be over. He loved the feel of Sans' body, caressing and driving into with nigh-reckless abandon that drove the smaller monster to cum over and over, crying his name in shouts of ecstatic pleasure...

"I learned from a devil," he replied breathily, gaining a wickedly appreciative grin from his lover. 

"Can that devil have more?" he asked in a calm, almost cooing voice. 

"All of it," Sans breathed, taking all of the pulsing arousal again, slower, groaning as he felt it pushing him closer already. He didn't have nearly as much stamina as Fell, even after plenty of practice. He felt the taloned hands on his own length, and was about to scold him for breaking the ribbon, but saw that it held just fine. Fell had shifted how it sat on his wrists, letting him wrap the blue shaft in both hands, pumping slowly as his grip tightened just enough, following Sans' motions as he rode him faster, panting out little moans. This increase in pleasure didn't let him last much longer, and Fell picked just the right moment to buck his hips upward and quicken his jerking, getting a nice, sky-hued squirt from Sans just as he arched up, crying out in a distinctly orgasmic moan. 

Panting, Sans barely kept upright, straddling his hips with his cock buried completely inside him, getting a wicked grin from Fell.

"My turn."


	3. Chapter 3

**Summary for the Chapter:**

> Oh hey look, next part. 
> 
> Back into Plotness!
> 
> EDIT; After some consideration, I changed Temmies to Floweys for Swapverse. I read another Fic with it and I saw it worked fine :p

Sans rested on his belly beside the larger skeleton, catching his 'breath' as the other kept lightly running a claw over his spine and hip. Usually he would doze off after that much attention from Fell, but he did want to bring up the proposal, so he was focusing on keeping awake and preparing how he'd start.

"You've got something on your mind," he said simply, knowing that Sans was still awake for a reason. The smaller skeleton nodded, pushing up to turn to face Fell, looking up with almost pleading blue eyes. Fell seemed taken aback at the gaze, one brow-bone shifting up.

"Today Alphys... uh, my Alphys," he clarified, "asked me something important, that we need to talk about."

Fell frowned almost immediately.

"It's nothing bad," he insisted quickly, seeing the dark expression coming over his sharp features, "its just very important." He found his voice breaking off, almost too shy to continue now. Fell pulled Sans closer in a snug embrace, lightly trailing a talon on the side of his skull.

"If it's important, then tell me," he said after awhile, finding himself disliking the unsure wavering of Sans' voice.

"W-well... they've talked about... having kids."

"And you were involved why?" his voice was suddenly taking that gravelly edge that Sans knew meant he was getting possessive, though it wasn't quite rooted.

"They can't," Sans answered softly, trying to coax the larger monster to calm down by leaning up and cuddling against him, a hand trailing along one of the thicker of his ribs.

"Sans."

Looking up, he saw the way Fell was glowering, the sort of look that meant he was getting angry and that his dominance was rearing up. If it weren't for the fact that he knew it wasn't directed at him, but at the conversation, Sans could see where it could be terrifying.

"You're dodging."

"Heh," he giggled nervously, then cleared his throat, "it's just... Alphys asked if I'd... be willing to, um... help."

"By help I assume you mean sexually."

"OH!" Sans puffed up defensively, pushing a hand up against Fell's cheek, as if to turn his face away, though there wasn't much force behind it, "you're making it sound bad!"

"Well considering they asked -my- mate," he started in a growl, only for Sans to shift his hands to hold to his jaw and look him in the eyes.

"Yes, they asked me, and I told them I would talk to you, -because- you're my mate. Because it's important that -you- know and have a say in it, Papy."

Fell groaned slightly, noticing just how much this conversation was affecting them both. He could practically watch as Sans grew more determined to convince him, while he already disliked the thought of anyone else touching Sans like that. Sans was HIS, damn it, and he wasn't-

"-Look- at me," Sans demanded suddenly, and they met gazes again. The smaller monster was practically pleading with him to agree to something that, to his very marrow, was against his nature. He absolutely hated that he was being asked to let anyone else see that side of -his- beloved, that anyone but him would hear the sounds Sans made. Those sounds were supposed to be HIS and no one else's to hear. He wanted to tell him he'd never let anyone else feel the moment that he was in utter bliss, not while he was alive... but the way Sans looked only made him realize how dearly this was going to mean to him.

"You want to that badly?" he asked, trying very hard to keep himself calm, despite how vehemently he did NOT want to let this happen. Sans nodded, blushing a little.

"I think... it'd be nice, to help them," the small skeleton said softly, though Fell could tell it wasn't just that as his motivation. He could almost hear now the desire for a child that his mate was having, after the other two had brought it up to him. He just hadn't imagined it would have been this quick for him to be party to the idea. Then again, Sans was a driven monster, once he had set his mind to something, he was well on his way to achieving his goal. Perhaps he'd been thinking about it longer than the last handful of hours. 

"Fine..." Fell finally breathed, feeling himself say the word even as he most assuredly was not happy about it, "but only under one condition." He saw the bright blues light up even more, grinning in agreement even before knowing what it would be. 

"I have to be there."

~ ~ ~ ~

Sans woke the next morning with just the blankets pulled up over him, and the towel he'd had on last night draped on the inside door-handle. Fell had left before he'd even gotten up, and it was barely 'light' out. Stretching, he felt that distinct soreness in his bones that he knew meant he'd be feeling the effects of last night's activities for at -least- the rest of the day. Which was fine by him, he wouldn't be held up in sentry or patrols by a bit of ache. It was only on training days that he knew he'd suffer for it, since Alphys didn't let up. 

A quick rub down before dressing, Sans hummed as he headed downstairs to start breakfast, figuring he'd make omelettes, though with a bit of cumin and mild sauce. Maybe even some tomato and peppers, he couldn't remember if he'd tried that before. He paused long enough to notice that Papyrus had slept on the couch, one of his sock-clad feet poking past the arm. He'd have to scold him for it later, he always slept more than usual the days after he'd spent the night down on the couch. 

The clatter of pans and bowls wouldn't wake him, so Sans didn't try to move quietly, working to whip up enough of the egg mixture to make several omelettes, so they could take a couple with them for snacks. Humming more as he was closer to finishing the third omelette, he heard the groan and creak of his brother getting up.

"Morning, lazybones!" he called cheerfully, sliding an omelette onto a plate for Papyrus, setting it and his own plate on the table. Moving tiredly, he slumped into his seat, elbows on the table, staring down at the omelette for a moment, as if processing what was going on in front of him. Sans had already sat down and was about to start on his breakfast when his brother spoke up.

"Y'know, you really need to remember to warn me when he comes over," Papyrus mumbled, "it gets really awkward to be coming up to say goodnight and hear things I really don't wanna be hearing." Sans blushed hard, squishing his face down into his scarf to try to hide just how blue his face was getting.

"Oh, s-sorry Papy... he kinda surprised me, so..."

"Don't," he interrupted, rubbing his temples, "don't tell me, I've got too many details in my head as it is. Just..." he sighed, letting his head droop to the side to rest on one hand, "try to give some kinda shout or somethin so I can stay a little less aware of my brother being railed?"

"OH!" he huffed, nearly stabbing his breakfast with the fork, "you BOTH get like that, making things sound -BAD-. It's not like us hav-"

"-PLEASE-, for all the stars, do NOT finish that thought out loud, Sans," the ever-suffering skeleton groaned, letting his head drop to the table with a clatter of his plate and fork, further words of defeat muffled in his orange hoodie. Sans decided to let that thought pass, and calmed himself down with a few bites of his omelette before speaking up again.

"Well, then you'll be glad to know, that I did get an answer for Alphys."

The table-and-sleeve-muffled response asked for further details.

"Yes, and I'll be going to see her and Undyne later today to let them know."

"And?" he finally emerged from his hiding place.

"And I'll let you know once I've asked them a few more things."

The narrowed gaze of unsated curiosity was all he got in response from his brother, who picked up his fork and began eating without further questions. Sans almost felt guilty, letting him hang like that, but he wanted to make sure they were okay with Papyrus knowing about the arrangement before bringing it up to him. They finished breakfast in silence, Papyrus getting up to smoke while getting changed for work while Sans cleaned up. 

The empty honey bottle and several cigarette butts sat unnoticed on the other side of the couch.

~ ~ ~ ~

Finishing his patrol, Sans found Papyrus dozing at his sentry station, giving him a good lecture about not letting his guard down on duty and how he should get up and patrol when he felt tired. Papyrus said something about he'd of slept in his room but for some problems he had no control over. Sans would have replied with something petty, but he just said he didn't have trouble falling asleep, he just wanted to be difficult, and left their conversation at that. 

"Maybe I should try figuring some way to make things easier on him, though," he muttered to himself for about the eighth time since he'd started towards the lab. Alphys was busy today, so he'd have to talk with Undyne first, and wait for the Guard Captain to get home. 

The trail to the Hotlands wasn't difficult, if anything he enjoyed going through the fields of Echo Flowers that grew in the moist, warm area between the two extremes. It got a little dark in places, and sometimes a swarm of Floweys would show up and interrupt with their non-stop chatter, but today it was peaceful. The magical 'light' of the underground was showing as nearing late in the day by the time he was into the Hotlands proper, the hardened ground puffing up dry dirt around his boots. As he went, he pulled off the heavier gear that was needed to keep comfortably warm in Snowdin, draping it over an arm and reaching the Lab by the time he was to his light armor. 

The smooth metal door opened almost automatically for him, letting Sans know that Undyne had spotted him on the way and unlocked the entryway. Putting down his warm outfit on a table that folded up off the wall, he continued along to a hallway, then a short walk to what he could call Undyne's living room. It was a bit of a mess, meaning Alphys either hadn't cleaned before heading to work, or had been away for a couple days. Undyne had been watching anime, the tv paused at a blurry action scene that he could see had several yellow and green smears of magical attacks. She had already shifted to give him room on the couch, though looked mildly confused.

"What's with the sudden visit, Sans?"

"Um, did Alphys say anything about talking to me?"

It took a few seconds before the merfolk blushed, her eyes widening a little before she coughed, covering her mouth with one hand as she mumbled something to herself, then waved him over, turning off the tv with a click of the remote.

"S-sorry, you mean about... y'know?"

"Yeah," he said as calmly as he could, though felt a little twinge of ache as he sat on the firm couch next to her. He waved at her concern, smiling slightly, "N-nothing's wrong. Actually I dunno if I should wait til Alphys shows up to tell you what Fell and I decided about it." 

Undyne prodded her fingertips against each other nervously, looking away before clearing her throat, nodding a little.

"N-no Alphys won't be back for another day or two, she's doing a full patrol and report this week," she told him. 

"Oh, well... uh, Fell said he'd be fine with it," he started, then rubbed his head alongside where his scarf met the smooth bone, "but, um... he did have one condition a-about it." Undyne didn't say anything, looking at him as she waited to hear about it. He chuckled nervously, then tugged his scarf a little. "H-he said he had to, be there, though..."

Her eyes somehow widened more, her face dropping in a mixture of shock and embarrassment, then paling as she got more nervous. Sans suddenly realized that likely it was Undyne that was going to be the mother, which he realized should have been obvious. Alphys wasn't the type to put aside her hard-won position of Guard Captain, and likely wouldn't be able to gain it back after however long she had to be away for a baby... and Undyne would be better able to continue her work regardless of her state.

"Oh, Undyne, I'm... I'm sorry but I know Fell... he won't hurt you," he said quickly, holding her hand reassuringly, "a-and it's just w-when we're-" he cut off, having a hard time putting it exactly in words, despite them both knowing full well what was going to happen.

"Well, if it helps, just think of it as, uh... breeding," she tried, getting an odd look from the skeleton. Undyne visibly recoiled, rubbing her eyes, "I'm sorry, I know it's a really awkward situation and if there was a way to make it less awkward..."

"N-no, I can.. try to think of it like that," his voice dropped, swallowing audibly. His voice came out smaller. "I want to help you an Alphys, and..."

"Sans?"

"I want to help," his voice raised, sounding almost desperate, then leveled to a gentler tone, "I mean, with the baby. With raising them."

Undyne smiled gently at him, crying visibly as she lunged an excited hug at the skeleton, laughing as best she could while hiccuping and trying to talk. Sans was surprised at the sudden embrace, but smiled as he gave her a genuine hug back.

"We'll figure it out."

**Notes for the Chapter:**

> I considered having FellPap say he'd think about it, but realized that all he'd do is angst over not wanting anyone else doing stuff with SwapSans vs making him happy, and it sounded a lil monotonous to write. That and the only reason I'd of bothered to do a time with him thinking it over would be to let me write some FellSans.  
> Also, in this version, both SwapPap and FellSans are straight, so sorry guys, no HoneyMustard here. Maybe next time ;3


	4. Chapter 4

**Notes for the Chapter:**

> lil quicker than I thought I'd be writing this part. BUT I do know the next part will be awhile, since I have a lot to sort thru in my notes first. There's more details than what's put in about monster breeding and such but I felt using all of it would leave none for explaining later.

Luckily for both of them, when it came to explaining things in technical detail, Undyne managed to subvert her awkwardness and explain how it would work to Sans.

"Monster breeding is persnickety," she said, shaking her head at his latest question - wondering if just donations would work. "Conception has to occur almost instantly for it to be viable, and even then it takes a little time before it actually develops into a monster baby, so if it doesn't take the first breeding, you won't know until a few days later when it can be tested for."

She paused momentarily, blinking, before adding in a slightly shyer voice, "Alphys already asked, I looked into that well before we considered asking for your help."

"Ok, so you said that being in heat would help," he blushed, rubbing his head, "b-but I had my last heat almost two weeks ago, so-"

"I thought about that too! You know we monsters have heats about each season, on average, but syncing heats takes awhile, even in mate-oh," she stopped, realizing she was telling the younger monster something he'd been taught in school - from the last year they attended, to be precise. All young monsters were given this sort of lecture, explaining about how their magic would build to a point that they would be very driven to relieve the over-stress of magic and hormones, and that usually it would pass given enough patience and exhaustion. But they also explained about how it was linked to a monster's sex drive and ability to produce offspring. A lot of the lecture was generalized, since each monster was different and needed to learn most of what their heat would do to them first-hand, but at least it gave them a sort of head-start on knowing what to expect. And also gave them a way to open the topic to their parents if they felt the need.

"Sorry, I'm just rambling," she said, then took a deep breath to steady herself, "s-so since it'll increase the chances of a successful breeding, I believe inducing heat in both of us, artificially, will be best."

"How would you do that?" he asked in an unsteady voice, suddenly rather nervous at the thought of what it might take to force a heat in either of them. Usually heats were uncomfortable at best, and complete torture to endure at the worst. Undyne knew exactly what he was worried about - her own worst heat had caused her to be a blubbering mess, more so than normal, crying and shivering constantly until it had passed. She didn't know what his worst had been like, since they'd never brought it up before, and certainly wasn't about to ask, but she understood his concern.

"It wouldn't last more than an hour or two, since it's a false heat," the merfolk assured him, blushing as she added, "I've done it before, to-to test if it would have made it easier with us. Me and Alphys I mean. To have the baby." She groaned, realizing she was starting to babble, then took another deep breath to compose herself once more. "It would only be to spike our magic and hormones to make it more likely to work the first time, since the less we have to try, the better for everyone involved."

"Y-yeah," he muttered, tugging at his scarf nervously. He still was having a hard time figuring how he'd manage to actually have se-breed, with Undyne. He'd never thought of her or any other female that way, he knew that much. It was getting harder to think about, so he tried pushing it aside to listen to the scientist as she tried to explain processes to him.

"S-so we each take the potion to induce heat, we breed, and a few days later we'll know if it took or not, is pretty much the gist of it," she concluded, and Sans realized he'd not been totally there for the last bit of what she'd explained. But since she gave him the short version, and that part sounded fine, he nodded.

"Now just need to wait til I can get Fell to tell me when he'll be available to... be there."

"Yeah, that part's the only thing that still gets me a little worried," she murmured, rubbing the back of her neck, "I mean, I know you said he's ...okay with it, and Alphys did tell me she'd rather not be present during... I dunno how I feel about that."

"It's the best I could do," Sans replied apologetically, "I could tell he's not happy about any of this. But I think he just didn't want to disappoint me by saying no, so I think, maybe, it's fair that he get to at least have that one condition kept."

"I get what you mean, Sans, I really do, just... maybe with the induced heat I can ignore him being there." Undyne shuffled her feet, the entire conversation slowing to a crawl, until she spoke back up with, "s-so, did you want to maybe watch some anime with me before you go?"

"Well, I guess we could finish the one you were watching when I got here. I don't want to be too much longer, it's getting late and I should head home soon to make- that reminds me!" he suddenly burst out, as he recalled about talking to his brother about it too, "would it be alright if I talked to Papyrus about this too?"

"S-sure, I don't see why not," Undyne answered, having jumped back at his sudden outburst, but in recovering, she headed back for the couch, waving a hand dismissively at her friend, "and it was almost over anyway, you head home. Send a message or somethin' once you hear from Fell then?" 

Nodding reassuringly, he rushed up and gave the merfolk a hug around her almost-lean middle - her diet gave her just the slightest bit of pudge - and smiled broadly, making her smile in response.

~ ~ ~ ~

"You've been awful pissy today, boss."

Glaring at his brother, Papyrus gave a rough growl, drumming his fingers on the table to the side of his plate. Sans chuckled as he whirled up another forkful of spaghetti. He spun the fork a little longer than needed, letting the tips of the tines scrape his plate in a way he knew irritated the younger, larger skeleton. He could see the sound grating at his brother's nerves, but knew getting him to yell was the best way to get him talking. Otherwise he would just growl and huff and generally avoid the topic.

"It's none of your business," he practically spat, scooping up a hefty bite of the pasta and ramming it into his maw. He did chew like normal, though, since he never wasted food.

"Blue bein' stingy with the tail?" he tried prodding, seeing the twitching of his brother's fangs around the chewing. So it did have to do with the other Sans. He leaned a bit to the side, letting the squealing fork annoy his brother a bit more this time before relenting with a slurp of the tasty meal. Papyrus glowered at him, hating when he let the noodles wag and flick sauce around.

"No, not that you'd care."

"Oh but you're always in a good mood when the lil guy's been generous with it, boss," he kept prodding, though knew it was a dangerous territory he was playing in, "so, if it's not the sex, what's on your mind?"

"Ugh, Sans I am really not wanting to spoil my appetite talking about this right now."

"Oh-HO so it's something -bad-," he prodded harder, letting his voice hit just the right, almost teasing tone.

"No, its just - shut up."

Sans let him stew over it a little more, taking smaller but noisier, messier bites of his dinner. It would crack his brother eventually, he knew. Or Papyrus would crack his head a little more. Either way, he was going to pry an answer out of the dangerous monster, whether he liked it or not. He was almost out of pasta when he was rewarded with a guttural hiss.

"For damn sake, Sans, STOP IT! I'm not in the mood for your games while I'm trying to think about how I am possibly going to deal with what he asked me!"

Bingo.

"What'd Blue ask ya, boss? Certainly nothin' good if you're this -flustered- over it."

"I AM NOT FLUSTERED, I AM IRATE. I HATE THE ENTIRE IDEA OF ANYONE ELSE DOING THAT WITH HIM BUT-" he caught himself, having seen the somewhat blank expression his brother was giving him. He seethed, slamming the fork down into the table hard enough to make it bounce and fly away to the floor. "Proud of yourself?"

"Wait, lemme get this straight. He ASKED you to let him fuck someone else?"

Papyrus roughly rubbed his brow, gritting his fangs with a groan.

"Yes and no, he was propositioned by his Undyne and Alphys to be the father of their kid."

"Shit," Sans breathed, his plate forgotten as he got up to go to the other side of the table and put a hand on his shoulder, "Paps, you ok?"

Normally being addressed by the nickname would enrage Papyrus, but being in their own home, the only safe space they could claim, it struck a cord, and he rubbed his fingers into his eyesockets, staving off what would be seen as weakness to other monsters here, but Sans knew better. They both knew better.

"Hey, lookit me," Sans said carefully, turning his head forcefully. The red pinpricks were halfway out, but flared up again as their eyes met, "hey, tell me about it, lil bro."

"He wants kids," Papyrus said flatly, his voice forced out of his teeth, "I couldn't say no to him about something like that, Sans. He practically begged me."

"Paps," Sans tried soothingly, his own sharp fingertips giving a gentle tap to the side of Papyrus' head, something that always got the taller skeleton thinking, he'd found. Papyrus groaned, pushing out of his brother's touch, lacing his own fingers together in front of him.

"I hate it Sans," he said in a low, raspy voice, "I hate the thought of what's going to happen, but I didn't want him to hate me for telling him no."

"Boss, Blue adores you," he said, flopping down back into his seat on the other side of the table with a grin, the golden fang glinting, "practically worships you. I've seen it, and I don't even tickle the ivories with 'em." Papyrus gave him a glare, but Sans shrugged in his over-exaggerated way. "He can't hate ya, boss. And hell, maybe you'll enjoy it, you've got some weird kinks."

"You are incorrigible, Sans." His voice tried to be spiteful, but his older brother could hear the tone of relief laced in. He grinned bigger, letting his fangs snap around the last bite of spaghetti.

"You know it, boss."

"Well, since you know why, then you'll be fine with taking a double shift this weekend," he said matter-of-factly, standing up with his plate to take it to the sink, where he knew Sans would eventually wash it, along with the other half-dozen plates waiting in the cold water. Unseen, Sans made a face, but did the same as his taller sibling before sauntering towards the front door.

"Welp, I'm gonna head down and see about scrounging up some action," he called over, wedging his feet into his sneakers that Papyrus insisted be left by the door. Papyrus crossed his arms, his voice dripping disdain.

"Again with the guard dogs?"

"Can't help that the bitches love it when I throw em a bone," he cackled, snugging his heavy jacket tighter around him before heading out, then leaned back inside just enough to add, "don't worry, I've got the weekend, so you can handle Blue and his maternal instincts."

The bone slammed the door shut after his jeering brother, pinning it for the time being. Papyrus growled again, but turned to start relaxing for the night. He still had several days before he would be free to visit again. He made a mental note to dismiss the bone summon from the doorway before he went up for the night. No sense in making Sans wake him up getting in.

**Notes for the Chapter:**

> hey look I did get to write some FellSans, sweet. I guess I'll add him again later if I want. Just for some fun aside.
> 
> Also, in this version, the Fell bros are more akin to regular Tale versions of themselves, as opposed to the abusive and jittery 'usual' ones. It's not seen as much in Underfell ones I've read, just felt like having FellSans be a lil more confident and such for this story.


	5. Intermission: Night at the Bar

**Summary for the Chapter:**

> Ok so I'm sorry this had had such a long hiatus, it's really being a butt to get the proper chapter 5 linking into what else is written, but... I decided to do a shameless insert for a little entertainment until the next one can come out. 
> 
> I'm sorry if you were hyped for the actual chapter, it's about... like a fourth of the way written, and I just need the stupid thing to cooperate so I can give you guys what you're really waiting for.
> 
> I guess til then, enjoy a lil smut with my OC Eldy~

He'd barely ordered his fifth drink from the fiery violet bartender before one of the dogs broke off from their group to sidle up to the skeleton, under the pretense of ordering something herself. Taking a quick lap at the shallow glass, she'd turned her attention to Sans in a decently disinterested manner.

"You wait'n on someone?" she asked in a bored tone. But the look in her eyes as she glanced over once or twice told him he wasn't off the mark.

"Depends on what you're bark'n at," he replied, giving a lopsided grin. She turned to bark something to the group of dogs she'd come in with - her outfit gave the impression she wasn't a guard, but likely a scout or archer - and they laughed something back to her as they continued whatever they were up to over at their table. After she finished her glass, she slid it over to lightly clink against his own, giving him a quick, almost subtle glance before she sauntered off towards the back hall, her arched-up tail swaying with each step. Sans chuckled to himself as he casually finished his own drink, giving it several long minutes before he got up and went to a different doorway.

"Took ya long enough," the feminine voice came from one side as he pushed the door shut behind him. Giving a low rumble of a laugh, the skeleton checked to make sure no one else was about, which garnered a similar chuckle from the canid. "Worried?"

"Well I wouldn't want anyone interrupt'n us, doll," he answered smoothly, running a taloned finger along her furred jawline, "why, did you think it'd be quick?" 

The doggish grin was all the reply he needed, pressing his teeth against her muzzle in a mock-kiss as he pushed up against her. She responded with a long lick, and arched up against him. A few moments of heated fumbling had them against the wall, next to some stacked boxes. Dragging his teeth through her neck-ruff, Sans chuckled as she kept licking at his skull, the sound of her tail thudding against the boxes the only sound beside their hungry panting. 

"Roll over," he rasped at her, and the dog giggled before turning to the side, her chest landing on the boxes, hips and tail perked up. 

"Good girl," he added as he slid his hands down to her belt, unbuckling it and working her pants down her hips. He left them snugged at her thighs, gripped her tail, and lowered to leisurely drag his tonguetip along her wet labia. She whined in appreciation, shifting against the thick ecto-construct as he lapped harder, pushing in just enough to tease. One of her legs shifted out, propping her weight as the other paw kicked slightly, in time with the strokes of his tongue. Laughing against her, he let it go deeper, the tip wriggling to make the canid yip with growing excitement.

"Tha's enough foreplay," Sans chuckled, giving one more heavy lick to the smooth form, shifting up to press the heated bulge of his shorts into her, making the dog pant as she looked over her shoulder at him, grinding back eagerly. 

"Yeah, let's get to why we're both here, huh?" she barely got that out before her tongue was lolling again, tail shifting in his bony hand with dogged excitement. He gave a humming nod, as if having taken a moment to consider before agreeing with the scout before hooking his thumb into the waistband of his shorts to let his cock spring free, not giving it much more than a bit of a rub at her wet curves before chuckling. 

"More of a hamburger guy m'self... but I won't turn down a _hot dog_ ," he mused in a rumbling laugh, and before she could respond with words, he thrust in to the hilt, garnering a throaty little moan as her hips perked up more, pushing into the cock buried in her. Grabbing her hips, he started a starved pace, the sound of bone meeting plush flesh barely audible over his grunting growls and her panting half-howl, half-moaning. 

He shoved harder against her, enjoying the brushing shock of fur against his hips. The scout made a whining growl, pushing back into his thrusts as they rutted in the back room, the single door wedged shut with boxes.

"You like that, then?" he chuckled, leaning down against the patch of black fur along her back. The dog nodded, panting feverishly.

"Yeah, c'mon stud I know you can do better," she panted back, hips lifting a bit higher against him. Sans laughed again, his teeth finding the thick fur of her neck and grabbing as he pulled at her hip and shoulder, her tail thwacking against his spine. He felt her clenching tighter around him just from that little bite, and he laughed around the fur in his mouth as he slammed into her, garnering a pleased yelp. 

Hardly five drinks in, and he'd already found a friend for the night.


	6. Chapter 6

**Summary for the Chapter:**

> Oh my freaking gods getting this written took way too long for how short it ended up being.
> 
> All thanks to SaturnWonder for helping kickstart my writing thoughts and drive for this.

**Notes for the Chapter:**

> Just so everyone knows, after the second ~ ~ ~ ~ is a lil smut, not much or detailed but just so those who prefer to not get into the erotica can skip it ;3

It was going to be a long day of training on his own, since Alphys was still away; for some reason, Papyrus had actually left the house early, before he had even woken up. Sans had had a quiet breakfast of oatmeal and juice before heading out behind the house. 

Stretches and balance postures started him out before he moved to summons, then a series of kicks and punches. Alphys had set up this routine to keep him limber, rather than for strength or exhaustion like the days he would get to spar with the much larger lizard monster. Taking a pause, he stood still and just breathed in, taking in what little he could scent around him. Cold was the first thing to notice, but the trees crept in after, then the light aroma of his own magic.

He grinned to himself before resuming his stretches for a few more minutes, then let himself topple back into the snow. Focusing on ignoring the chill trying to make him get up, Sans lifted his hands, palms up, to work on summons again. Five bones hovered above him, solid and glowing as he worked to make each move differently; up and down, the second rotating in place, one like a pendulum, another going end over end like a boomerang around the group, and the fifth held as still as possible. 

He had added the fifth a little over a week ago, having gotten the hang of four, but he was having trouble holding it in place while the others danced about. He would have to refocus and hold it again before he could resume, he thought with a sigh. Keeping that single one still had been harder than he had thought. Giving it another try, he managed to hold it for a few seconds before it tried to follow after the one circling. 

At that point, he keenly felt how damp he was getting from laying sprawled out in the snow, and decided to call it good for now, and go for a jog to the edge of town and back. Picking himself up, he patted the snow that clung to him before stretching up in an almost luxurious arching before kicking up into a slow jog, steadily working up a little faster to get into the right pace. He hummed to himself, eyes glinting bright against the snowy air and his breath drawing in before it puffed in a stream out of his nostrils. The bouncing motion of his jog had his bandanna flapping about, and he paused when he reached the turning point, giving another stretch from his toes and up his spine. It was nearing lunch, so by the time he got home again, he'd be hungry and ready for a break. Giving a few shakes of his legs to kick away any clumps of snow, the little skeleton started back, his smooth pace the same as before, not feeling quite flagged yet. He squealed internally at the feeling - his stamina had gotten better! Before he'd need to take a longer pause at the turn to catch his breath, but now he'd barely stopped to stretch. Sans was just passing the library when he felt a bit of the hunger rumbling in his 'belly'. The ecto hadn't formed yet, but it would before he got home, since it'd announced itself. 

He hit the first step of their porch, now feeling the sting in his chest from the cold air and the exertion. He was just about to open the door when his phone went off, pulling it up to see a message from his brother. 

-not gonna be home for dinner, don't wait up-

That was unexpected, but he did occasionally have night shifts. But on the same day as going in early? Sans was going to call, when he got another text, this time from Undyne.

-I got to talk to Alphys, doesn't like the thing with Fell but she agreed after I explained.-

-He was supposed to be visiting this weekend. Would you want to set it up when I hear from him?-

Sans felt all of the things he'd been thinking about jumbling together in these past few minutes, and the little skeleton went inside to slump on the couch, staring at his phone as he considered calling Papyrus. Usually his brother would have mentioned have a night shift, though maybe it'd been pushed on him on short notice. Instead, he tapped out a response to Papyrus before going over to make himself lunch.

-Ok, don't forget to eat something Papy. I'll see you tomorrow?-

~ ~ ~ ~

The rest of the day he'd been texting with Undyne and continuing his training exercises until he was far too tired to continue. She'd told him that Alphys had decided to just keep away in general, since she shared his older sibling's dislike of the other skeleton. Dinner and a bath finished out the bulk of his evening, then he was lounging in bed reading, still occasionally messaging his merfolk friend. Luckily both were happy to not focus on the plans for the weekend, since after a few of the texts it had started making both obviously feel a little awkward.

He got another message just as he was dozing off, Papyrus said he was sorry he missed the evening with him but yes, they'd have breakfast like always and he loved him.

Smiling as he replied with a simple "okay, love you too Papy", Sans nestled the phone back in place and cuddled more into his blankets with a little hum.

~ ~ ~ ~

He woke up to the sound of his own phone alerting him it was dead. But he'd been charging it... except when he lifted it, the plug wasn't in the outlet. _Stars, really?_ He must've tugged it loose somehow. Fixing that, he tried to lay back down and get a few more hours of sleep, but kept tossing and squirming. Cracking his sockets open, he shivered as he felt a little needy, his magic already pulsing with want as he considered it.

It had been awhile since he'd felt like masturbating outside of his heats, usually he was quite settled until Fell would visit and get him worked up. But he couldn't ignore that he was horny now, and obviously it wasn't going to leave him alone to just doze back off... and it would likely help him in the end.

His palm rubbed along his arousal, already starting a firm pace, his other hand creeping under his shirt to tease at his ribs, right where his mate always liked to toy with him. It gave Sans a little rush, closing his sockets and imagining it was him, rubbing and tending his need in the middle of the night.

Just light touches, steady pumping... Sans' breath caught as he gave a whimper, writhing under the hand he pretended was Fell's. Even if it was a little off, he could hardly tell right now. He could almost hear the playful whisper of his mate in his earhole, getting him right to the edge and shushing his noises with a pause. Stopping only long enough to make him wriggle and beg. 

Shivering, he stifled his soft moan with a hand, panting as he came down into relaxation. He'd have to remember to strip his bed in the morning, he thought to himself as he adjusted and was lulled quickly back to sleep.


	7. Chapter 7

Sans woke up feeling perfect, eyelights bright as he sprung up from bed, even bouncing a little on the mattress before he slid off. He was so used to starting his routine, that the little skele almost forgot to take the dirtied bedding away to set up for washing. Blushing as he made sure he got all of it, he bundled the sheets up and carried them over to sit beside the banister at the top of the stairs. Pausing, he looked down and saw Papyrus strewn on the couch. He pouted. 

It meant his big brother had stayed out far too late, and Sans would have to give him an earful about it later. For now he let the big lazybones sleep, getting his shower and starting the laundry before deciding on making a pretty simple breakfast of eggs and bacon with toast. The coffeepot making its siren roar was what roused the lanky monster, drifting over to fill a mug with the dark brew.

"You were out late," Sans said, only just a tinge of accusation to his words. Papyrus hummed into his coffee and was filling the second cup as he replied.

"Muff wanted to talk," he said, "got off shift kinda late an went to chat with her a bit longer than I realized."

"Well, I'd like to talk too," Sans replied in a cheerful chirp, "so hopefully you're awake enough once we're done eating!"

"Bout your uh... whatever it was? The other day?" Papyrus took his plate over and sat down as Sans followed, nodding as he joined him at the table.

"Yes! I asked and Undyne said it wold be alright," he paused to start on his bacon, since he liked it when it was still hot and super crisp, and Papyrus didn't even pause, his honey-slathered toast disappearing first. Sans finished up on his eggs before elaborating. "They're wanting to have kids, and I figured you'd have some good advice! Undyne was explaining to me about how the surrogate process would-"

"The -what-?"

Sans paused, the tone having actually shocked him, looking up from his plate with bright eyelights. Papyrus seemed well awake now, his breakfast, his tiredness, everything else, forgotten.

"No."

"I haven't even-"

"You're too young," Papyrus snapped, hands pressed flat on the table, as if he were about to stand up, "you have no idea what they're asking you."

"Pap, I'm not a child," Sans insisted, trying his best to not add petty insults. He didn't think Papyrus would have been like this. He steadied his thoughts again, sighing. "I only brought it up because Alphys and Undyne didn't mind you knowing about it."

"Then they should have talked to me first, would have saved -everyone- a lot of wasted time."

"You're not listening. I am going to help them," he said, trying to not lose his level headedness, "I thought you'd be at least somewhat happy about this."

"What, exactly, is there for me to be happy about, Sans? You're dating a monster that I can't stand, and now two of our friends are taking advantage of you for their own selfish reasons."

"Fell is my mate, and has been for over a year," Sans corrected, trying to keep himself from blowing up, keeping his voice as calm and firm as he could right now, "and they are not selfish, or taking advantage of me. It was -my- choice to help them, and I am going to."

"No, you're not."

"Papyrus, you're not listening. You don't decide for me. If you don't want anything to do with the baby, then fine, I'll just visit to see them."

"Sans, it's not-" Papyrus cut himself off, resting his forehead against a hand as he sighed, deep and slow, seeming to droop and grow weary even as he sat there, "I just don't want you to get hurt. You don't know what it's like, raising a kid."

The little skeleton pushed up from his seat, moving over to his brother's side, quiet for a moment as he watched him seem to just look tired and worn out.

"And I want to know," he replied, taking his brother's hand, "Pap, I agreed because I want to. I know you worry about me and that you're just trying to be a good big brother, but I've been an adult for a long time." Lifting up on his toes, he gave a gentle kiss to the taller skeleton's brow, he rubbed that larger hand with careful fingers. "I'm not going to disappear... just because I'm not a baby bones anymore."

"You're still so young..."

"Papy, look at me."

The taller skeleton looked at his brother, the bright blue eyes both demanding and begging for his brother to see what the younger of the siblings was trying to do. He could see for a time, the little monster that he'd raised for years, and each blink made him a little bigger, a bit older, until he stood in front of him as the mature adult he was faced with. 

Papyrus rubbed the heel of his palm into one of his eye sockets, stifling a sniffle before gripping Sans' fingers.

"You'd better not, because that kid's going to need you."

Sans reached up to hug around his brother, the clack of their skulls touching rousing a smile.

**Notes for the Chapter:**

> Most of the conversation with Papyrus in the first part has been sitting for MONTHS, guys. Just getting to this point was a pain in the arse I can tell you what.
> 
> Again, thanks to Saturn for giving me some thoughts on how to fit it in and continue <3


	8. Chapter 8

The next few days of waiting had Sans fidgeting and anxious, but at least after the last hour at work, he came home and was making sure everything was ready for Fell to visit. The first night was usually a movie while they cuddled on the couch, so that at least wouldn't be different from routine. The movie was already queued up and he'd made sweet potato fries and lettuce wraps with chicken, which he knew Fell had liked the last time he'd made them. He was was busy finishing up the meat when he heard the three-pace knock his mate used.

"I'm in the kitchen!" he called, and heard Fell come in, knowing that being removed from cooking just to answer the door was a crime to both of them. He moved in and hugged around the other's shoulders with a quick kiss to the top of his skull.

"You're making the wraps again," Fell commented with a softness to his tone that had Sans smile even brighter.

"I finally remembered to get the right seasonings for the sauce," he replied, tipping his head over to get a kiss, "would you mind watching it for me while I go change? It just needs to simmer a bit more." When Fell nodded, he hopped off the step stool and hurried upstairs, and the taller skeleton folded his arms to look down at the pan with a slight frown. He really did like this meal, just... he knew that tomorrow was going to be... unsettling.

"Oh, you're here."

Fell let his gaze slide from the stove over to his smoking doppelganger, quirking a brow before turning back to stir it.

"Yes, I'm having dinner and going to watch a few things with your brother. He went upstairs to change."

"What? letting him actually stay dressed for once?" he quipped, and mentally screamed at himself for being such an idiot. For even bringing it up. Fell glanced back with a sharp glare.

"I don't just come over here to have sex, you know."

"Uuuugh," he groaned, knowing full well that he brought that on himself, and gladly would have stuffed the prior comment if he'd of fucking thought first. Heading up to his room, he passed Sans, but didn't stop, and the small skele paused to watch as his brother disappeared behind the door, shrugging and heading down in his comfy pajamas. Honestly, by now he'd stopped scolding him for smoking on his way to his room, where he'd smoke more. Just so long as he didn't linger in the rest of the house, it didn't stick, and he didn't feel like trying to bother Papyrus tonight.

"I've got a movie set up already," Sans added as he started piling meat on the wraps, "I talked to Undyne the other day, she said we'd be able to come over on the first ferry if we wanted, she'd just need me to call and let her know."

"Blue, could we... not talk about this tonight?" Fell asked, his voice wavering slightly, which had his mate look up in concern. His arms were still folded, and he didn't meet eyelights for a moment. "Just... I'd like to spend time with you, not... with the idea." 

"Okay," he replied, reaching over to take one of Fell's hands and hold it, "I'm... I'm happy you're okay with this, though. As well as you can be, I mean." Fell nodded, though he grit his teeth together a bit harder and sighed when he let go of his hand to finish the wraps.

"I just didn't want you to be upset," he said after Sans had finished setting the plates up, and was handing his to him. Sans looked up again, eyelights gone bigger and softer. He put his plate down to hug around the bony middle of his lover's body.

"Papy... I just... I want to help my friends, and... if there really were a better way to handle it, I would do that. I didn't ask this to hurt you."

"No, I know..." Fell interrupted, his voice scratching, almost as if forcing the words out before he could bite them back, "I know it's not... if I'd of known you wanted kids, we could have talked about it more."

"Papy, you live in another universe, you visit on weekends," Sans started, as if they needed a reminder, "I... didn't think you'd want kids, either. It's only been a year and honestly I didn't really -know- I wanted them myself until Alphys mentioned it. It kinda opened a door for me to really think about." 

"We'll talk about it more sometime, then," Fell said, taking Sans' plate and handing it to him, "because if you wanted something, I'd of wanted it too, even if we'd have to work around some things. For now, let's just enjoy our evening like always." Sans smiled up at his mate, taking his dinner as both went over to the livingroom to spend the evening cuddling.


	9. Chapter 9

**Summary for the Chapter:**

> There is smut in this one, but the smut is tied up in plot as well. Like, over-arching plot. This is a fic about pregnancy and babies, after all.

Sans cuddled in a bit closer as he felt Fell waking up behind him, the larger monster always seemed to sleep deeper when he visited, and only on occasion would Sans wake him up on purpose. He liked the way his mate would lean into him, would nuzzle against the back of his neck or skull and hug him in closer when he was fighting the vestiges of sleep. The way his breaths became shorter and shallower, building slowly. 

Fell always preferred waking here with his lover in his arms, the smaller skeleton an ever-present comfort, feeling the way he was just right there, waiting for him to wake. The times Sans would wake him were few, and usually only if he'd been sleeping for longer than either of them usually would permit. This morning, he felt the desire to just stay in bed, to not go out and meet the situation he knew was drawing closer. He hated it, but it was for Sans. He would almost always do what Sans wanted, because he just wanted his mate to be happy. He hadn't even considered that he'd want kids, hadn't thought about the possibility, and now that it had presented itself, Fell did want to talk about it. Not right this moment, of course, but if it was something Sans really wanted for them, together, then Fell would want to see it work. 

He ran his hand along that smooth ribcage in front of him, stopping at the flat of his sternum. "Do I have to get up?" 

Sans managed a soft giggle, rolling to meet eyelights with the other skeleton. "Yes, I'm afraid so, Papy. I know you're not happy, but Undyne already told me the time frame she has set up, and... well..." he moved to grip the larger hand in his own, taking a soft breath that sighed out, "if there was another way, I'd do that. But they tried, for months, to find a different way. And it's better to get it over with, right?" 

"I suppose," Fell started, and realized he sounded bitter, shaking his head before tightening his grip on that other hand, "I'm sorry. I'm trying to not be such an ass about it. For your sake." His voice lowered and he leaned to press his brow into the crook of Sans' neck, giving a slight groan, "stars, this better work the first time. I don't know how I'm going to handle today, let alone if you have to do it -again-."

~ ~ ~ ~

Undyne let them in, looking flushed and nervous as she led them over to a spare room in the lab quarters, muttering in apology. As if there were a proper etiquette for this sort of arrangement, or that they'd planned one. She gulped back more apologies as they got to the room, a lone bed seated there.

The skeleton shivered after he'd gotten undressed, leaving his bones bared as he held the potion Undyne had given him, licking his mouth before he opened the bottle, sniffing at the liquid and feeling himself flush a little just from the scent. Throwing his head back, he drank it was fast as he could, gasping when it was emptied into his being, feeling it already penetrating his bones. It smacked of overwhelming magic, making his head hum and buzz as it filled him, running through his marrow and giving him an overall warmth that came to him with heats. It was at once exhausting and invigorating, balancing between collapsing from the strength of it and bursting with need.

"T-that kicks really hard," he stammered, blushing softly as he placed the bottle on the table as carefully as he could. He could feel every tingle in his bones pulse over-hard, and knew that if this was a real heat, he'd be a furiously horny mess for days. Luckily, it wouldn't last long, she'd said, and he tried his best to focus through the haze.

"Ok so since he -has- to be here," Undyne puffed slightly, looking put off by the larger male, "just... sit over there or something." Indicating a chair to one side of the room, not really looking at Fell for more than a moment. He frowned more, but grudgingly walked over to take a seat. She had to admit, through her glaze of heat, she could see what Sans saw in the taller monster. He was a prime example of a naturally dominant alpha monster, with the strength and presence to back up his protective and commanding attitude.

"If you'd quit staring at me," he said in a terse voice, snapping her out of her thoughts, and turning to see that Sans had come up closer, blushingly. He was exactly the right match for Fell, she noticed, he held and smoothed the rough edges while also allowing his mate to be possessive and fill his drive to be needed. She smiled slightly, unbuttoning the front of her lab coat.

"W-well, no sense in delaying," she heard herself say, taking one of Sans' hands to have him help her out of the coat. She'd worn only her bra and panties with the coat, and felt a bit of a warm shiver creep up her spine as he took the fabric.

"Undyne," he said softly, though kept glancing over at Fell, who looked anything but interested in the near-nude merfolk.

With a blush, she began wriggling out of the underclothing, feeling suddenly very prepared, and sat on the bed. When she looked up again, Sans was still in that spot, watching her and holding the lab coat. She noticed he kept averting his attention to Fell, as if waiting for instructions, while she sat there in an increasingly flushed heat. She'd taken her potion before Sans, so it was locked into her far better than him. Then Undyne realized that skeleton, while clearly shivering with heated arousal and lust, hadn't gained the symptom of that need.

"Sans," she tried, calling with a shivering, lust-tinged voice that had been given to her by the potion. He looked at her, but she knew something just wasn't clicking in the small monster - desire. Despite his drive, his body and its false heat just were not working together.

"Here, let me help," Fell suddenly growled, and before either could protest, had picked up Undyne, taken her seat on the bed, and pulled her to rest back against his ribcage, "obviously it's a good thing I was here, you'd never get anywhere," Fell shifted Undyne with ease, pulling her to lean more against him as he pushed his hips slightly forward, pulling at her knees so that they would splay back against his femurs. Sans blushed bright blue where he stood, still holding her coat, as he watched her be manipulated in place.

"H-hey," she protested weakly, only for Fell to lightly run a few claws along her gills, rousing a breathy gasp from her.

"I can stop and take Sans with me if you want," he said, though he knew it was an empty threat. He knew this meant a great deal to his small companion, so now he was going to make sure Sans got to help. From what he'd watched in those several minutes of alternating between fiercely upset and growlingly accepting of the situation, he knew now that Sans needed more push than the merfolk could give him. Undyne gulped slightly, more out of her still-lingering intimidation of Fell than anything else, shaking her head a bit.

"You okay Undyne?" Sans asked, moving a bit closer to them, the coat being knotted up in his balled, shaking fists. She glanced at Sans before she nodded, her smoothly-angled fangs showing in a light, anxious grin.

"H-he is try'n t-to help..." she said, blushing hotly as she felt him run his claws on her gills again, making her quiver. Fell beckoned his mate closer with that look he always gave him when he was ready to play with the smaller skeleton, and Sans could see just how much he was doing this for him, flushing hotly with bright, eager eyes. Giving Undyne a reassuring smile, he moved up against her, shivering at the odd sensation of her smooth scales against his bones. Fell eased an arm past Undyne's side to rest on Sans' hip, getting the blueberry-hued eyelights to turn to his fiery-red own.

"Try to relax," he told them both, his voice low and relatively soft as he took away the lab coat. Sans loved him more than ever from just that gentle tone alone. Shyly moving a hand, he traced along Undyne's gills as Fell had earlier, gently pressing into the sensitive pink flesh. Undyne gasped as his lean, hard fingers intruded into the soft skin past her scales, biting her lip. Fell took one of her hands in a light hold, raising it up to cover Sans' hip, his longer, bony talons extending past her manicured claws.

"Um-" she blushed, looking over at Fell with curious surprise. He met her gaze as patiently as he could manage, then lowered it to keep from frightening her, focusing on the task.

"Start by rubbing up along the bone," he explained, guiding her hand along the curve of Sans' ilium towards the spine, "then dig your claws in, just a little."

Undyne was going to ask why, but seeing as how the larger skeleton -was- his lover, she did as she was told, and carefully slid her nails on the hip-bone, eliciting a gasp from Sans that she'd never heard before. Flushing, she continued to his lower spine, and she found a spot that likely was used to the slight dig of claws from the minuscule notching in places. Placing her short claws in the notches, she gave a light squeeze, making Sans softly groan in pleasure, his fingers in turn pressing into her sensitive gills. Fell took her other hand now, moving it up to the crook of Sans' jaw.

"Here too," he nearly purred, and she obeyed, growing more fascinated by the moment. As her thumb-claw dug into a light groove, Sans' mouth flopped open as if by a switch, pale blue tongue lolling past his teeth as a set of fangs slid loose at the sides and back. Sans shivered visibly, his arousal beginning to show, glowing in the same hue as his conjured tongue. A grating chuckle behind her almost drowned out her curious gasp at the skeleton physiology. She'd read about how their bodies worked, but hadn't seen any of it in practice. The fangs in particular reminded her of those her own kind bore.

"Be sure to run your claws on him," she was told as she began to move her hand down again, and drew her short nails along his jaw bone. She blushed harder, an almost-purple color coating her gentle features.

"I-if you want... " she started, her voice small and shy, before clearing her throat nervously, "y-you can... help more."

Fell raised a brow at the comment, but since he was already helping, he figured more wouldn't hurt. It might even keep his possessiveness from flaring up, since he seemed to be the one in control of the situation. Leaving her to claw at Sans, his own hands moved to her lean frame, pressing and rubbing to search for the spots that elicited noises from the merfolk. Whenever he found one, her fingers would lock a bit, digging harder into Sans and rousing a moan from him. Continuing his search, he felt her heating up, her pulse quickening and lending a violet-blue tinge to her body. Giving one of her pert breasts a rough groping, he had her panting as hard as his own mate, who had been taking well to her blunt-clawed attention.

After a little while of the prodding, talon-fueled foreplay, her took her by the elbows and pulled Sans closer using her grip on him, sandwiching the scientist between the two skeletons. Feeling Sans' firm cock up against her, Undyne gasped and pulled him a little closer, and Fell's hand moved to guide the glowing blue arousal to her damp entrance, leaving his fingers in place to tease at them both.

"Ah... oh!" she gasped, feeling the larger bony hips behind her push her forward more, and Sans reacted to the warm entrance by thrusting forward, moaning softly as his hands grasped desperately at her. Fell traced his fingers over his, gripping reassuringly at the smaller hand before he leaned over Undyne's shoulder to clack a kiss to his mate's brow; he then lowered his jaws to bite at Sans' neck, rousing a moan and a reactionary thrust into the merfolk. Had she been in the mindset to examine it, she'd of been quite surprised at how amorous the bone-grinding biting was for the two skeletons. Undyne returned the hip-thrust, but leaned back into Fell as she dug her nails into Sans's scapula and arm, increasing his thrusts. She could also feel that Fell was reacting to his mate's heated moans, a decidedly non-bony appendage pressing at the curve of her purple-flushed rump.

"P-Papy," the smaller skeleton moaned, hips working against her as she heard the distinct grating of bone grinding against bone as he bit harder, Sans' tongue drooling over her shoulder and chest. Rather than release the grip on his neck, Fell rubbed his free hand up against the curve of Sans' jawbone, pushing at the side of his tongue to let him gnaw slightly at his thumb. Moaning around the talon, his tongue curled, now brushing up against Undyne's gills, making her gasp smoothly. The tip of his tongue searched into the wet, hot slit, curling into the invitingly heated flesh. For a long while, they kept this odd-three-way embrace in relative silence, aside from the sexually charged gasps and moans of the two smaller monsters, Fell surprisingly quiet despite his throbbing, dribbling arousal at the swell of her buttocks.

Sans' starry-eyed, lustily dreamy expression continued almost slavishly as Fell slid two more digits into his mouth, giving him more to gnaw on and have his tongue retreat from Undyne's gills. This entire time, he had kept his other hand firmly against the arch of Undyne's groin, feeling the pubic bones under her flesh as Sans thrusted between his thumb and fingers into her, growing more hectic the longer and harder Fell bit into him. He knew not to dig his fangs any deeper, since he didn't particularly enjoy the taste of marrow.

"Haa-ah-" Sans murmured around his tongue and Fell's fingers, and the skeleton chuckled darkly, letting it vibrate his mate's bones and drive him closer to his peak. Pushing his thumb hard against Undyne's clit, he felt the pearl of sensitive flesh shift easily under his motions, as well as the throaty moan she gave from the touch. It likely had her clench around Sans, which made him groan into his fingers as he doubled his efforts, thrusting as deep as he could with Fell's hand in the way.

"AH!" Undyne exclaimed, the combination of rubbing and thrusting driving her near the edge, legs jolting up to pull Sans in by the hips, squishing her even more between them and putting pressure back on Fell's cock. The larger skeleton growled at the heavy rubbing, but didn't deny it felt rather nice, even if it was a bit different from what he preferred. Loosing his fangs from Sans, he hummed thoughtfully a moment before scraping the sharp points along her neck, right over her gills, making her shout in ecstasy as the distinct arch of her back and tensing frame signaled her orgasm. The name of her own mate was able to be somewhat heard, though not clearly, in the jumbled cry.

Sans was next to shout his lover's name as the wet tightness of the fish monster drove him to come into her as her legs locked tightly over his hips and spine. Fell, of the three, did not have any input, instead just quietly enjoying the feeling of Sans pushing her back into his fluid-streaked arousal. A few moments' panting, and Undyne slumped back, almost forgetting Fell was there, before stiffening, her legs sliding off Sans' hips.

"W-well, a couple days and I can test-"

"Oh we're not done yet," he interrupted smoothly, and for a moment, Undyne considered the large cock against her backside with a shiver, but the larger monster moved out from behind her and to their side. "He may not last long, but he has wonderful recovery, don't you precious?" Fell asked in a rasping purr, his teeth pressed softly against Sans' temple. The smaller skeleton, still hilted in her, nodded shyly.

She watched, distractedly fascinated, as Fell slid his talons along Sans' ribs where they connected to the spine, dipping between and stroking audibly. Fresh whimpers rose from him and her eyes widened as she -felt- him responding to the touches, arousal twitching.

"He's got another, oh, two or three in him, at least," Fell mentioned almost casually, talons going to the notches in his lower vertebrae, then grinned, "though with this heavy a heat, I'd bet we get five."

"-F-five-?!" Undyne sputtered, practically lighting up in a bright blush all along her body. The look Fell gave her was equal parts cruel, hungry, and erotic.

"I thought you wanted to make sure it took. Loading you up will certainly increase the odds."

"I j-just... I didn't-"

"Didn't think what Sans was capable of?" he asked as he shifted against his mate, leaning over the smaller forms as his teeth found Sans' neck again. Their scents and sounds had driven him into just as eager a state, and the flushed blue skeleton was whimpering in need as he felt that familiar hard shaft against him. 

"Safe word is dandelions," Sans whispered against Undyne's cheek, and she flushed somehow even darker violet.

"W-why would I need to know that?"

"Because Fell can get... pretty rough," he answered, gasping as the taller skeleton was working at his entrance, "e-especially when he's worked up..."

He groaned, his own bright blue tongue drooling out past his fangs on the side as Fell hilted in him, pushing Sans deep into Undyne again. The smaller skeleton now had no real control over his hips, rather it was the larger monster now setting their pace, and it was quickly developing into raw ferocity. By the time Sans had gotten his fingers hooked against Undyne's sides, the pace was swift and hard, making both of them moan in unison. Remembering the skeleton's bite from before, Undyne arched over a little and set her fangs against San's clavicle and bit down softly, arms thrown around his ribcage as she felt him tighten his grip on her. Fell growled, but didn't stop her, rather he gave a wicked grin and thrusted harder, forcing them down against the bed even more.

~ ~ ~ ~

Fell's guess had been right, and by the time the potion had worn off of both smaller monsters, Undyne was dizzy with exhaustion. Glad that at least the bed was soft, she let the two skeletons shift her up to rest, draping the blankets over her. Sans was a little shyer than before, now that he was his usual self, but part of him was glad that, perhaps, this would give his friends the help they'd asked for. Leaving the lab, Fell held his hand, since Sans had insisted that he didn't need carried, but was a bit wobbly.

"Thank you," he said, looking up at his tall mate. Fell tilted is head, looking thoughtful for a long while before a devious grin curved his features.

"Well, I figured if you were going to be breeding, you might as well enjoy yourself," he said in a smug tone, and Sans flushed with a barely-repressed squeal, covering his mouth as he made half-choked sputters that were attempted words. Fell noticed the very clear flush along his features, and he stopped to lean imposingly over his mate. "Precious... I think I know just what to do with that."

**Notes for the Chapter:**

> *whispers* Sans has discovered a breeding kink *stops whispering*  
> Also there is more to come _hehe come_ but it might be a little longer before another update is done, since these ones were mostly written, and it was just the connecting writing that needed done.


	10. Chapter 10

**Notes for the Chapter:**

> WELL HI THERE

When Sans closed the door after Fell left, he turned around, and yelped as his brother appeared almost out of nowhere. He could tell he was drunk, and dear stars he reeked like a skunk monster.

"Papy?" he asked, shifting into the more than likely blurry field of vision, a mix of emotions roiling in his soul. He was glad he was okay, but what had prompted him to get so thoroughly _trashed_? He looked worse than he had in months, and he choked back a whimper. It was his fault. For all the stress and arguing, all the things he'd pushed on his brother all at once in the last month. "Papy?"

"Shhh," he murmured, waving a hand that was shaky with booze, his entire body seeming to follow it, "n-not righ now SSS- _*hiccup*_ Saahns." He seemed to be trying to figure out exactly _where_ he was right now, looking around at the house and blinking stupidly. Everything seemed to sag around him, as if his very spirit were pulling things in against him. "Wh... eeers'a... um... oh."  
  
Sans watched as Papyrus made his way around the couch, pulled out _more_ booze and honey and cigs from stars-knew-where and started in on them. As if he hadn't had enough already?!  
  
"Papyrus!" he snapped, going over and snatching everything out of his hands, "you are not having any more tonight!"  
  
"Why?"  
  
The simple, stern question threw him off a moment, but he pulled away a step, to make sure his brother wouldn't try to take the hateful things back. Sans puffed up, gathering himself after having had such an odd day, and this was just the topping on the cake.  
  
"You can't be _doing_ this to yourself, Papy! I'm sorry I've been so hard on you, but please... I still need you, even if I'm an adult."  
  
"Nah," he replied, the words fumbling out of his mouth, "you'll be alrigh... not like ya needed me b'fore. I jus' go inna way all th'time..."

He kept trying to swing his slow, impaired arms to get to the vices Sans had behind his back, and the little skeleton pulled away again. Only he went too far for the other to reach, and his drunken stupor didn't let his mind know that. He fell forward onto the floor, grunting as he just stayed there. Looking even more like a mess, and seeming to not care.

"Papy, what's wrong? Why are you doing this?"

He didn't get a clear answer, just a string of garbled words and noises that might have been coherent, had the older skeleton been even a little sober. Sans felt tears prick at his sockets, and he went over to the kitchen and threw the junk away. He didn't say a word as he dragged his half-sleeping, wasted brother up the stairs and into bed. He stopped once he pulled the blanket up off the floor, and more tears trickled down his face at just how much trash that one blanket had been hiding.

There was more under the bed, empty bottles for honey and alcohol alike, a tiny mountains-worth of cigarette butts and bundles of smelly, burnt paper that he didn't know _what_ to call them. But all of it he gathered up, cleared away, and put into a trash bag.

How much had he been turning a blind eye to? Of what Papyrus had hidden from him, let alone what he'd just... not seen? Sans wiped his face on his sleeve, tears continuing to fall. He though his brother had been doing better, had been drinking and smoking less... but had he just been ignoring it? What had he missed that he could have helped?

Sans sat on his bed, looking down at the book in his hands and reading silently to himself. He wondered how long he'd been hurting his brother. How long Papyrus had been hiding. Had he always been hurting him? Even when he was little and had no idea things were bad, had Papyrus been hurting then too? He wanted to make it better, but it seemed everything he'd tried had only made it worse. Being an adult, being a child, being here... he just wanted to help his brother.

 

~ ~ ~ ~

 

The morning left him feeling stiff and sore, tears dried in his sockets, and when he sat up, he saw that Papyrus had seemingly crawled his way into the younger sibling's room and dozed back off at the side of his bed. Clutching a book. Like he had been reading to him. Sans covered his face and tried to wipe the tears away, tried not to cry, and failed at it every step of the way. He didn't move from the bed, just sat there and cried, and felt all the worse when he heard his brother waking up.

"G-go b-b-bbback t-to sleep," he blubbered, knowing he wasn't going to do as he asked. Knowing Papyrus wasn't going to listen, and it was his fault for being selfish.

"Y'know I can't," he mumbled, pulling himself up to prop his chin and folded arms on the bed. He was still in his dirty clothes, and looked like hell, but he still had a bit of a smile. Even though he was probably hungover and in pain.

"Why, Papy?" he asked after several long minutes of just trying to steady himself, "what do you need me to do?"

Papyrus turned his head to the side, looking away. He watched, but as always, no answers came up on that long skull. His face never really betrayed much of what he was actually thinking, aside from contemplative or pinched or...

"I worry all the time," Papyrus said under his breath, "I'm just trash and I got this great lil bro, and how the hell did that even happen?" Sans' tears had him look away again, and he picked at a stain on his hoodie. "Now you're just... gonna be a dad, and I dunno..."

"I want you here," he said, voice strained, "you're the b-best brother, Papy... you've sacrificed and d-done so much for me, and I let you down. I d-d-did... didn't help you. I m-missed that you were h-hurting and-"

"I hid, bro," Papyrus interrupted, I hid it from ya an... it's not yer fault."

"HOW?" he yelped, "HOW is it NOT _MY_ fault?! I make you miserable, I pester you and make you upset enough to-to DRINK and drive yourself CRAZY and how's it NOT _MY FAULT_?!" The silence from his brother was heavier than any weight in the world, and Sans wiped his face with another sniffle. "I want to help, and all I do is hurt you."

"It's... really complicated."

"I'm not going anywhere," Sans said, turning to face him, pulling at the dirty hoodie and not letting up until he was sitting on the bed in front of him, "please. _Please_ Papyrus, talk to me. I can't leave you like this anymore. I can't let you pretend you're okay."

It was quiet for almost an hour, but Sans waited, watching Papyrus sit there and pick at his sleeve. As he let him think. He didn't rush him, or pry for him to start, or get up and go make anything to eat, even thought he was really getting kind of hungry. Papyrus had to be miserable, hungover and needing food, but... he seemed to be wanting to talk, since he'd come over and stayed. He knew he could leave if he wanted.

"I really just want you to be happy," Papyrus said in a small voice, sounding as if he'd been turning it over in his head for years, "and I don't know how to let go of you."

"Why would you have to let go Papy?" Sans asked, reaching over to pull his arm closer by part of his sleeve, "I'm right here, I'm not leaving you alone."

"I have to let go, because... because if I don't, it'll mess you up and make your life harder." Papyrus pulled his arm back, tucking it with the other in his lap, "you're an adult, you're moving on with your life, you're... you have a mate and you're starting a family and... and I'll just hold you back."

Sans pushed up, dragged himself into that sullen, smelly lap, and grabbed that long face to make Papyrus look at him.

"You have NEVER held me back, Papyrus. All my life you've put me ahead and made sure I was okay even though I knew I was sad and lonely and that... that I could only ever count on you at the end of the day," Sans said, then hugged into his brother's front, still sobbing, "I need you, Papy. You're my big brother and I love you no matter what. Please... let me help."

It took a bit, but Papyrus shuffled in closer and hugged the little monster, pressing a soft kiss to the top of his skull. "You are."

**Notes for the Chapter:**

> Oooof this took a bit outta me to write up. But I think with this out of the way, I think I can get along with the next few chapters. There is still a bit more planned~


	11. Chapter 11

Sans had let Papyrus sleep the rest of the weekend away (after having eaten and washed, of course), and the morning before work, was apprehensive about meeting with the Captain again. He hadn't thought much about what all he and Fell had _done_ with Undyne, had figured that Alphys would want to know nothing about it. The scientist hadn't quite said that, but considering her mate hadn't even wanted to be anywhere near when... when it happened... Sans bit on his glove a moment, trying to decide what to do. It would usually be a training day, but he'd not heard from Alphys. He'd not messaged her either, really, but it was a very different situation they were all in right now.

"Hey bro," the lanky monster said, emerging only minutes before they had to leave for work. He still looked worn out, and he wasn't fully dressed, needing socks and shoes and his hoodie, but he was up, and he was getting coffee, and really, after everything, Sans was glad for that alone. He didn't harp at him, even though his first instinct had been to hurry him, to keep them from being late.

"I made you some breakfast," he said, looking up from tightening the strap on his boots, "it's in the microwave."

"Thanks," Papyrus said, taking it out to put the omelette on a piece of bread. They were out of honey, Papyrus had consumed all of it on his breakdown bender, but Sans had conceded that they could get him more. That he didn't need to rush with improving... even though he'd originally wanted to cut him off completely.

"Sans?"

"Huh?" he said, blinking.

"I said, I can eat on the way..." his brother replied, sounding as if he'd not expected Sans to space out. That was usually his territory.

"S-sorry, Papy, no, you should eat before we leave. It'll be fine."

Sans pushed up off the floor, turning around and retrieving his phone from the coffeetable. Still nothing from Alphys or Undyne, but Fell had just sent him a little heart, his usual morning greeting to let him know everything was okay. Pressing the top of the device against his chin, he hooded his sockets shut and hoped his friends were okay too.

By the time they left for work, they both knew they were late, and Sans didn't go on about it. There was a lot that he had to restrain himself on, to help his brother. He'd been pushing him too hard, he knew that... but he'd thought it had been going well, that Papyrus had been handling it and going along with the pace he'd set. He'd been proven wrong in a very clear, bad way.

Not the _worst_ way, he wasn't that naive... the worst, he shuddered to think of it. But he'd gotten the message, loud and clear. He'd been too demanding, too hard on his brother. He'd asked too much, too fast. Now he needed to rectify that, give him a little space to recover before they found something he _could_ improve with. They'd need to talk more about it, they'd agreed to that, and have to do it when Papyrus wasn't floor-kissing drunk.

Work went as normal, see the dogs, do the routes, recalibrate puzzles, head to Papyrus' station and head home to make dinner. His brother was even mostly awake when he got there, so that had him smiling. But then he remembered that he was supposed to have trained today, and had heard nothing. Was Alphys upset at him? Did she regret what they'd decided, what they'd asked? Was the reality of it worse than she'd imagined? He bit down on his glove again, using it as an excuse to pull the tough blue leather off his hand to keep Papyrus from asking anything.

Sans worked on dinner, the phone nearby, in case anyone messaged him. He wanted to hear something, anything, from anyone. He didn't know how long Undyne had to wait, she'd said a few days but he wasn't sure how many that meant. Three? A week? He felt a slight roiling where his ectoform made magic guts, and he felt sick, pushing away from the stove and taking several long, deep breaths. He knew he was psyching himself out. He was worrying when maybe it was just nothing. Maybe Alphys was just busy, and hadn't thought to message. Maybe Undyne hadn't had time. Maybe they were wanting to wait and find out for sure before telling him anything.

_Maybe they didn't think it would hurt this much._

He wiped the tears on his cheeks away. He just wanted to KNOW. Did they still want to be his friend? Even if they felt perhaps this hadn't been the right choice after all, that perhaps it'd gone wrong. He was feeling his breath hitch at the sound of a light _ding_ from his phone, and he stared at it for a long time. It wasn't a particular noise, nothing different than anyone else would message him with. He stared, and waited to hear if another would come.

A second _ding_ , and he was grabbing it up, opening the first.

Alphys, apologizing for forgetting to message him, saying she'd been busy... then saying she'd see him tomorrow for training, and that he'd better not be late.

He cried with relief, glad at least that his friends weren't angry with him, even if they'd asked his help. He'd thought about it, and if they had been angry, he'd of understood. It was a risky decision, the whole thing, but... it had been for something they'd wanted, even if it caused some temporary hurt and confusion. He'd been confused when he'd finally lost the induced heat, when he'd looked over at Undyne, worn out on the bed and trying her best not to cower under Fell's very presence. Doing her best to not feel embarrassed about what all had happened, tried not to squeak out her words. Fell hadn't lingered in the room, had done his best to not hurry them.

Sans remembered talking with her a bit before she'd dozed off, holding her hand while she lay under the bedding. He'd gotten dressed, with Fell's help, and was telling her he'd like to come back to see some anime with her again soon. Then he'd left with his mate, coming home to spend time together. The darker monster had been considerate and comforting after everything that had happened, not bringing any of it up.

They'd had dinner and watched something, Sans couldn't remember what, but he'd been there, been holding him close and stroking along his skull and shoulders. Had been present without being demanding. Sans had appreciated it, every moment and touch. It had been romantic, now that he thought about it, for Fell to be whatever he'd needed him to be at the time. He smiled as he thought about it, Fell holding his hand and gently rubbing his thumb over the back of his wrist.

Tapping out a reply to Alphys, he sent it before sending three hearts to his mate, then went back to finish making dinner for him and his brother.

 

~ ~ ~ ~

 

Panting as he slumped to the ground, Sans dispelled the bone-summon of a mace that Alphys had told him to work with today. It had been heavy, thicker than his usual weaponry. He'd had to remake it three times before she'd given him the nod. He'd not lasted half as long as with his more comfortable, familiar polearm, the weight and balance entirely different, but now that he thought about it, Sans had enjoyed the way it moved. He didn't have to put as much power into keeping the momentum, only in stopping and starting it. He heard Alphys move past him, sitting herself down with her own twin-bladed halberd propping her hands up.

"Been a rough weekend," she said, almost sounding jovial, then shifted her good eye to the skeleton, "we're not sure yet, but... we think maybe."

"Really..." Sans said around another pant, wiping his face of some smears of dirt, showing off more bruising from the rough workout. He steadied himself, pushing up and holding an all-fours pose  before getting up to his feet, pushing one hand against his femur. Stars, she'd gone all out on him today. "Is Undyne okay?"

"She's been better, but... she does seem excited. Everything's pointing to positive, but she can't get a full one-hundred percent call yet." Alphys slid her hand along her headspines, pushing the halberd back and forth a bit.

"Do you want to talk about it?" Sans asked, keeping his spot, rather than moving to sit beside his friend. He didn't know how her mood really was quite yet. It took a few minutes, but the reptilian monster gave him a firm nod, and he went over to sit with her.

"Yeah, actually. I thought I wouldn't, thought maybe could just, I dunno, pretend or something... but... well it's been a bit rough on me too." Scooting a bit closer, Sans put his hand on her arm.

"It... it was really weird, actually, after... the potion wore off. I just felt like I had no idea how I'd managed," Sans admitted, his voice small and tiny, "I never thought of her like that, or you, or any other female. It just... never drew my attention otherwise."

"I get what ya mean," she chuckled, giving a toothy grin, though she didn't look at him. Sans let them both sit in silence for a bit, then patted the thick yellow muscle.

"But I did it because you asked me, because... it's something you both wanted. And that I want," his voice dropped, "being asked... it kinda showed me how much I'd been wanting the same. Kids, I mean."

"I didn't know if I was ready, to be real honest... but I want what Undyne wants," Alphys gave a deep breath, pushing herself up and grabbing her huge axe, "an it makes me happy, know'n it might be time to really get that place cleared up and ready fer a baby."

Sans watched her swing the halberd, watched as she still had so much energy left to burn, while he felt like his second wind had ended somewhere between trying to figure out how to manage the arcs for the mace and how to not make his hand ache by stopping the hefty weapon in time to block or deflect. Looking down at his gloved hand, he flexed the leather-covered digits, and could tell he'd mostly failed in keeping his metacarpels from bruising. He'd have to make sure there weren't any large cracks, either, or he'd risk breaking his hand, and needing major healing for the next week or so to keep it from getting too weak.

"That's enough for today," Alphys said, breaking him out of his thoughts, "make sure to take it easy this evening, an do your magic training tomorrow." He was surprised to hear the word 'easy' come out of her mouth, but she'd given a clear order, and he saluted with a grin before turning to head home.


End file.
